Journal articles: 'Water Mathematical optimization'

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D’Ambrosio, Claudia, Andrea Lodi, Sven Wiese, and Cristiana Bragalli. "Mathematical programming techniques in water network optimization." European Journal of Operational Research 243, no. 3 (June 2015): 774–88. http://dx.doi.org/10.1016/j.ejor.2014.12.039.

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Cojanu, V., and E. Helerea. "Applying the mathematical optimization model in water distribution management." IOP Conference Series: Materials Science and Engineering 789 (June 6, 2020): 012011. http://dx.doi.org/10.1088/1757-899x/789/1/012011.

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Alabdulkader, A. M., A. I. Al-Amoud, and F. S. Awad. " Optimization of the cropping pattern in Saudi Arabia using a mathematical programming sector model." Agricultural Economics (Zemědělská ekonomika) 58, No. 2 (March 5, 2012): 56–60. http://dx.doi.org/10.17221/8/2011-agricecon.

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A mathematical sector model has been formulated to optimize the cropping pattern in Saudi Arabia aiming at maximizing the net annual return of the agricultural sector in Saudi Arabia and ensuring the efficient allocation of the scarce water resources and arable land among the competing crops. The results showed the potential for Saudi Arabia to optimize its cropping pattern and to generate an estimated net return equivalent to about 2.42 billion US$ per year. The optimized cropping pattern in Saudi Arabia has been coupled with about 53% saving in the water use and about 48% reduction in the arable land use compared to the base-year cropping pattern. Comparable weights was given to different crop groups by allocating about 48.4%, 35.4%, 13.1%, and 3.2% to grow cereals, fruits, forages, and vegetables, respectively. These findings were in line with the national strategy to rationalize the cultivation of water-intensive crops in favour of highly water-efficient crops.  

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Lee, Jui-Yuan, Cheng-Liang Chen, Tong-Lin Wen, Denny Kok Sum Ng, Dominic Chwan Yee Foo, and Tzu-Chi Wang. "Synthesis and design of chilled water networks using mathematical optimization." Applied Thermal Engineering 58, no. 1-2 (September 2013): 638–49. http://dx.doi.org/10.1016/j.applthermaleng.2013.04.024.

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Wang, Ke Yan, and Qi Sheng Wang. "Mathematical Model and Numerical Experiment of Photovoltaic Water Pumping System." Advanced Materials Research 772 (September 2013): 653–57. http://dx.doi.org/10.4028/www.scientific.net/amr.772.653.

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This paper presents the engineering analytical models of photovoltaic (PV) water pumping system from electronics theory, and some mathematical models of system components have been established. Studies have shown that the minimum unit water cost may not be reached only with the control strategy of maximum output power of the system. Therefore, system optimization is very necessary to reducing the capacity for every unit of pumped water, which is based on the design optimization theory and has shown its economics.

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Toma, Petrică Daniel. "Sizing and Simulation for Optimization of a Water Pumping Installation Using Fuzzy Logic." Ovidius University Annals of Constanta - Series Civil Engineering 22, no. 1 (December 1, 2020): 85–93. http://dx.doi.org/10.2478/ouacsce-2020-0010.

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Abstract In this article we present the way how to create a program in the Scilab-Xcos environment with which it can be dimensioned, mathematically modeled and simulated a water pumping installation. The mathematical equations implemented in the program with which the dimensioning and simulation are done are presented. Fuzzy logic was used to generate the pump characteristics.

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Zagorska, V., and U. Iljins. "Optimization Of Parameters Of Heating Elements For Floor Panel Of Piglets Resting Places." Environment. Technology. Resources. Proceedings of the International Scientific and Practical Conference 2 (August 5, 2015): 92. http://dx.doi.org/10.17770/etr2011vol2.1010.

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The article deals with problem solving of mathematical physics using the method of separation of variables optimizing heating element – optimizing water tube parameters (tube material, radius, insulation thickness, choosing appropriate surrounding environment). For ensuring piglets comfort, concrete floor panels heated by electric current or hot water are used. If an electro-heated cable in the panels body is placed, than amount of heat conducted from the cable is the same along all the length of the cable. If hot water circulating through tube is used, than amount of heat energy taken off the heater decreases along its length. The aim of the research is to create the mathematical model of a water tube, were water temperature is gradually decreasing. This model is needed to make precise calculations of the heating panel for piglets, to ensure equal temperature distribution over the upper surface of the panel, taking into account mathematically calculated temperature decrease of the heat source.

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Hu, Chang, and Dang Sheng Li. "Research of Crop Water-Saving Irrigation Optimization." Applied Mechanics and Materials 737 (March 2015): 771–75. http://dx.doi.org/10.4028/www.scientific.net/amm.737.771.

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According to Luoyang rainfall data from 1951 to 2011, this paper discussed the distribution characteristics of rainfall in the whole year. It analyzed summer maize growth period with the coupling of water consumption. It set up the estimation model of summer maize water consumption, the mathematical model of yield and water relationship, and then analyzed its mutual relations. The experimental results showed that the water requirement and rainfall distribution would fit well during summer maize growth. But summer maize growth stage should be irrigated suitably in the dry and median water year.

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Lenhard, Richard, Katarína Kaduchová, and Jozef Jandačka. "Numerical Simulation of Indirectly Heated Hot Water Heater." Advanced Materials Research 875-877 (February 2014): 1693–97. http://dx.doi.org/10.4028/www.scientific.net/amr.875-877.1693.

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This paper describes a mathematical model of heating hot water for indirectly heated hot water heater. Using the established mathematical model was carried out simulation of the device to change its geometrical parameters. Based on the results of simulations was carried out optimization of indirectly heated hot water heater for hot water. Subsequently been made CFD simulations of the device, and those were compared with a mathematical model to verify the accuracy of the proposed mathematical model of heating hot water for indirectly heated hot water heater. Computational methods based on finite volume methods (CFD method) have proved very useful in optimizing indirectly heated hot water heater.

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Cioc, D., and A. Anton. "Real-time optimization simulation software modules for water networks." Water Supply 3, no. 1-2 (March 1, 2003): 279–86. http://dx.doi.org/10.2166/ws.2003.0115.

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Several mathematical models and commercial computer codes are available to assess the behaviour of a hydraulic network both at peak demands and in 24 hour operation. Could a new model add some value to the prestigious existing ones? Are we really at the end of the research path in this field? These questions are to be answered in the present paper. A new concept of optimization is presented for water distribution modelling: a concept based on life-cycle cost analysis. Introducing a minimum number of parameters, technical and also economic, the authors were able to elaborate a mathematical model for optimization. The corresponding computer code’s capabilities are related both to the design of brand new networks and to the rehabilitation of old ones. The speed of the code allows, among others, a real-time optimization simulation for an existing network, making it a valuable operational tool. Finally the code has been tested on several networks and has been validated with very good results, being a simple tool that is easy to handle and capable of exchanging input and output data with practically any other similar software or graphic tool.

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Lefrançois, Simon, Philippe Doyon-Poulin, Louis Gosselin, and Marcel Lacroix. "OPTIMIZATION OF ICEBERG TOWING VELOCITY FOR WATER SUPPLY." Transactions of the Canadian Society for Mechanical Engineering 32, no. 3-4 (September 2008): 537–48. http://dx.doi.org/10.1139/tcsme-2008-0036.

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A mathematical model for determining the optimum towing velocity of tabular icebergs is presented. The optimization problem is formulated in terms of a benefit function that takes into account the ice mass delivered and the total fuel consumption for the tow. Results indicate that the optimum towing velocity is mainly affected by the water-to-fuel cost ratio. It is shown that towing icebergs from Antarctica to South Africa is a profitable way of supplying fresh-water provided that the towing velocity is optimized with the proposed method.

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Kheybari, Siamak, and Reza Salehpour. "The optimization of the paddy field irrigation scheduling using mathematical programming." Water Supply 15, no. 5 (May 19, 2015): 1048–60. http://dx.doi.org/10.2166/ws.2015.062.

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In planting rice, a significant amount of irrigation water is required to prepare the farmlands and do transplanting and this is directly related to the number of machines and workers available; that is, the more the length of plowing and transplanting process due to the lack of required machinery and labor, the more the water volume consumed. Therefore, in such conditions, it is important to have an appropriate planning for the optimized allocation of machinery and labor for the agricultural lands. Determining the optimal times of opening and closing valves based on the factors directly influencing the volume of the water in paddy fields is also of great importance. To meet the above conditions and by using linear and non-linear programming, two different models are developed in this article, with the purpose of reducing the time period of plowing and transplanting operations and also lowering the water consumption, respectively. Comparing the outputs of these two models with the real irrigation situation demonstrates the efficiency of the proposed models.

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Varzi, Manijeh Mahmoudzadeh. "Crop Water Production Functions—A Review of Available Mathematical Method." Journal of Agricultural Science 8, no. 4 (March 11, 2016): 76. http://dx.doi.org/10.5539/jas.v8n4p76.

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<p>Crop water production function is the relationship between obtained marketable yield and the total amount of water used by plant through evapotranspiration. Different mathematical expressions have been derived from field experiments to predict yield knowing water use. Such expressions provide a powerful tool in water allocation optimization. However these functions are commonly confused with the relationship between available water and crop yield. This paper reviews functions that describe crop water production, the context they can be used for, and their strength and weakness.</p>

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Mi, Xiao Juan, Jing Cheng Xu, Ju Wen Huang, Lan Luo, Yong Li Liang, and Guang Ming Li. "Application of Mathematical Programming Method for Water Supply and Recycle Network in Titanium Pigment." Applied Mechanics and Materials 367 (August 2013): 347–50. http://dx.doi.org/10.4028/www.scientific.net/amm.367.347.

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Water integration method is widely used in water minimization. Water minimization has great benefits to environmental and industrial sustainability. Both freshwater consumption and wastewater discharge can be minimized by practicing water system integration. Sulfate process (SP) is an important and mature method to produce titanium dioxide (TiO2) pigment. A large amount of water is consumed and a large quantity of effluent is discharged, which may cause water resource waste and serious environmental pollution. The paper presents Mathematical Optimization Method for water minimization of a titanium pigment plant event in China. The result of this study shows that mathematical optimization method has been effectively applied for the titanium pigment plant, and the freshwater consumption is reduced by 45.97 %.

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Ismail, S. M., A. I. Omara, D. O. El-Ansary, and V. Hamada. "WATER PRODUCTION FUNCTION AND MATHEMATICAL OPTIMIZATION OF REGULATED DEFICIT DRIP IRRIGATED PEACH." Misr Journal of Agricultural Engineering 32, no. 3 (July 1, 2015): 1077–100. http://dx.doi.org/10.21608/mjae.2015.98193.

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Deng, Chun, Wei Jiang, and Xiao Feng. "Deciphering Refinery Water System Design and Optimization: Superstructure and Generalized Mathematical Model." ACS Sustainable Chemistry & Engineering 6, no. 2 (January 5, 2018): 2302–15. http://dx.doi.org/10.1021/acssuschemeng.7b03754.

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Tangwe, Stephen, Michael Simon, Edson L. Meyer, Sampson Mwampheli, and Golden Makaka. "Performance optimization of an air source heat pump water heater using mathematical modelling." Journal of Energy in Southern Africa 26, no. 1 (March 23, 2015): 96–105. http://dx.doi.org/10.17159/2413-3051/2015/v26i1a2225.

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In South Africa, there is an ongoing constraint on the electricity supply at the national grid to meet the demand. Eskom is implementing various measures such as the Integrated Demand Management and the promotion and encouragement of the use of energy efficient devices like an Air Source Heat pump (ASHP) water heater to replace the high electrical energy consuming conventional geysers for sanitary hot water production. The ASHP water heater market is fast gaining maturity. A critical mathematical model can lead to performance optimization of the systems that will further result in the conservation of energy and significant reduction in global warming potential. The ASHP water heater comprises of an ASHP unit and a hot water storage tank. In this study, a data acquisition system (DAS) was designed and built which monitored the energy used by the geyser and the whole building, the temperature at the evaporator, condenser, tank outlet hot water, tank inlet cold water, the ambient temperature and relative humidity in the vicinity of the ASHP evaporator. It is also worthy to mention that the DAS also included to a flow meter and two additional temperature sensors that measured the volume of water heated and inlet and outlet water temperature of the ASHP. This work focused on using the mathematical equation for the Coefficient of Performance (COP) of an ideal Carnot’s heat pump (CHP) water heater to develop basic computation in M-file of MATLAB software in order to model the system based on two reservoir temperatures: evaporator temperatures (Tevp) of 0°C to 40°C (approximated to ambient temperature, Ta) and condenser temperatures (TCon) set at 50°C, 55°C and 60°C (approximated to the hot water set temperature of 50°C, 55°C and 60°C) respectively. Finally, an analytical comparison of a CHP water heater to the practical ASHP water heater was conducted on a hot water set point temperature of 55°C. From the modelling results, it can be deduced that at 0°C Tevp, the COP was 5.96 and 2.63 for CHP and ASHP water heater respectively, at a hot water set temperature of 55°C. Above 20°C Tevp, the rate of change of COP increased exponentially for the ideal CHP system, but was constant at 0.01/°C for the practically modelled ASHP water heater.

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Costa, R. H. R., C. T. Zanotelli, D. M. Hoffmann, P. Belli Filho, C. C. Perdomo, and M. Rafikov. "Optimization of the treatment of piggery wastes in water hyacinth ponds." Water Science and Technology 48, no. 2 (July 1, 2003): 283–89. http://dx.doi.org/10.2166/wst.2003.0132.

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This work investigates the optimal management of water hyacinth ponds for the improvement of piggery waste treatment. The optimal harvesting strategy for the water hyacinth was studied using a single mathematical model. The water hyacinth optimal harvesting problem was formulated as an optimal control problem that was solved by application of Pontryagin's Maximum Principle. The optimization of the water hyacinth control in the pond indicates that the plant density should be reduced whenever it reaches half of the maximum capacity for growth. Two experimental systems were used to validate the mathematical model, one in real scale and the other in pilot scale. The results demonstrated the feasibility of the proposed harvesting strategy. For example, a comparison of the total nitrogen removal in the different pilot ponds confirmed the modeling results, in that the performance of the pond maintained with 50% water hyacinth cover was better than the others.

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Xu, Wen Yuan, Bing Xiang Liu, Xing Xu, Na Hu, Hao Hu, and Ying Zhu. "Water Quality Model Parameters Estimation Based on Particle Swarm Optimization Algorithm." Advanced Materials Research 610-613 (December 2012): 1925–29. http://dx.doi.org/10.4028/www.scientific.net/amr.610-613.1925.

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Water quality parameter is the basic data of the river water quality mathematical model for forecasting river water quality status. In this paper, the parameter estimation problem of the analytical model, which is used to describe one-dimensional tracing test data of river streams with tracers instantaneously injected, is converted to the function optimization problem. And particle swarm optimization algorithm is applied to solve this problem. The experimental results show that the particle swarm optimization algorithm can estimate the water quality model parameter values regardless of whether the randomly sampling data has noise.

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Meisheng, N., Z. Kezhao, and L. Lianquan. "System Optimization of Stabilization Ponds." Water Science and Technology 26, no. 7-8 (October 1, 1992): 1679–88. http://dx.doi.org/10.2166/wst.1992.0611.

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In order to study the system optimization of stabilization ponds, this paper has set up its mathematical model. A series of optimization systems of stabilization ponds are recommended through optimum method under different flow rate, land price and total BOD removal rate. The three parameters are discussed, and the optimum method is improved.

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Ngo, H. H., S. Vigneswaran, and H. B. Dharmappa. "Optimization of Direct Filtration: Experiments and Mathematical Models." Environmental Technology 16, no. 1 (January 1995): 55–63. http://dx.doi.org/10.1080/09593331608616245.

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Iljins, U., I. Ziemelis, H. Putāns, A. Šķēle, and J. Navickas. "Optimization of the Parameters of Solar Water Heating System." Environment. Technology. Resources. Proceedings of the International Scientific and Practical Conference 1 (June 26, 2006): 353. http://dx.doi.org/10.17770/etr2003vol1.1994.

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In order to investigate the possibility to increase the efficiency of a flat-plate solar collector the mathematical model of the collector has been worked out. By solving the Laplace heat transfer equation at the boundary conditions accordingly to the construction of the collector, the obtained solution gives possibility to simulate on a computer the construction of the collector in dependence on physical, thermal and economic values of materials used for the construction. The computed results by theoretical formulas with experimental results obtained on special laboratory equipment have been compared and good concurrence acquired.

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Hallmann, Corinna, and Leena Suhl. "Optimizing water tanks in water distribution systems by combining network reduction, mathematical optimization and hydraulic simulation." OR Spectrum 38, no. 3 (May 16, 2015): 577–95. http://dx.doi.org/10.1007/s00291-015-0403-1.

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Fu, Yun Xia. "Multi-Objective Parameters Optimization Design of Single-Pipe Ring-Type Mixing Water Oil-Gathering Pipe Network." Key Engineering Materials 467-469 (February 2011): 1285–90. http://dx.doi.org/10.4028/www.scientific.net/kem.467-469.1285.

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Single-pipe ring-type mixing water oil-gathering process is often used in the oil-gas gathering and transportation system of low permeability oilfield. In order to improve the economic benefits of exploitation and construction of low permeability oilfield, multi-objective parameters optimization mathematical model of single-pipe ring-type mixing water oil-gathering process is built with the targets of minimization of pipeline construction investment, thermal energy and power energy consumption. The model belongs to the mixed-discrete variable nonlinear optimization problem. According to the structure characteristics of the model, multi-objective parameters optimization mathematical model is changed into the single-objective optimization by using linear weighting method. Then the single-objective optimization is solved by hybrid genetic algorithm. Network optimized design of a block of oil-gas gathering and transportation system is conducted by the model mentioned in this paper, and the result is that pipeline construction investment reduces 12.4 percent, thermal energy consumption reduces 14.4 percent and power energy consumption reduces 12.4 percent.

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Liu, Yang, Zihang Zhang, Lei Bo, and Dongxu Zhu. "Multi-Objective Optimization of a Mine Water Reuse System Based on Improved Particle Swarm Optimization." Sensors 21, no. 12 (June 15, 2021): 4114. http://dx.doi.org/10.3390/s21124114.

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This paper proposes a general hierarchical dispatching strategy of mine water, with the aim of addressing the problems of low reuse rate of coal mine water, and insufficient data analysis. First of all, water quality and quantity data of the Narim River No. 2 mine were used as the research object; the maximum reuse rate of mine water and the system operation rate comprised the objective function; and mine water quality information, mine water standard, and mine water treatment speed were the constraints. A multi-objective optimization scheduling mathematical model of water supply system was established. Then, to address the problems of premature convergence and ease of falling into a local optimum in the iterative process of particle swarm optimization, the basic particle swarm optimization was improved. Using detailed simulation research, the superiority of the improved algorithm was verified. Eventually, the mine water grading dispatching strategy proposed in this paper is compared with the traditional dispatching method. The results show that the hierarchical dispatching system can significantly improve the mine water reuse rate and system operating efficiency.

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Yang, Shufeng, Lifeng Zhang, Jingshe Li, and Kent Peaslee. "Structure Optimization of Horizontal Continuous Casting Tundishes Using Mathematical Modeling and Water Modeling." ISIJ International 49, no. 10 (2009): 1551–60. http://dx.doi.org/10.2355/isijinternational.49.1551.

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Tian, Jiandong, and Guifang He. "Optimization design method for urban sewage collection pipe networks." Water Science and Technology 81, no. 9 (April 27, 2020): 1828–39. http://dx.doi.org/10.2166/wst.2020.200.

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Abstract In this study, a secondary subsystem mathematical model is established under the condition that the layout of the sewage collection branch, trunk, and main pipe network projects is fixed. The sewage collection branch and trunk pipe network projects are treated as the research objective by taking the minimum annual cost of the sewage collection pipe network projects as the objective function, the longitudinal slope of the pipe section and the economic flow rate of the pipe section as constraints, and the diameter of the pipe section as the decision variable. A first-level subsystem mathematical model is established by taking the sewage collection branch, trunk, and main pipe network project as the research object. A large system mathematical model is established in the same manner. This model can be solved using the large system secondary decomposition–dynamic programming aggregation method, and the optimal diameter for each pipe section can be obtained. A regional sewage collection pipe network project in Taizhou city was considered as an example for comparative analysis before and after optimization, and the results verified that the optimization method proposed in this study can solve this complex large system optimization problem.

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Wang, Wei Zhuo, and Jian Min Bian. "Study on Measures for Solving Accident of Water Distribution System." Advanced Materials Research 918 (April 2014): 149–53. http://dx.doi.org/10.4028/www.scientific.net/amr.918.149.

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Measures for solving accident of water distribution system are main factors on urban pipe network developing. This research is done by mathematical modeling and optimization based on EPANET. The potential scheme have been proposed at the very beginning of the accident; then, the best result is chosen by calculating. The method is tested by solving a hypothetical case. The result shows the superiority of the optimization method in view of economic and reliability point, convergence and calculation efficiency in the calculation.

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Chen, H. W., and Ni-Bin Chang. "Water pollution control in the river basin by fuzzy genetic algorithm-based multiobjective programming modeling." Water Science and Technology 37, no. 8 (April 1, 1998): 55–63. http://dx.doi.org/10.2166/wst.1998.0308.

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Designing water quality management strategies is often complicated by the difficulty in simultaneously considering large amounts of relevant data, applicable submodels, competing objectives, unquantifiable factors, nonlinear characteristics, and uncertainty during parameterization. Mathematical optimization techniques offer promise in identifying optimal or satisfactory strategies that may be used as benchmarks for decision making. Newer optimization techniques such as genetic algorithm (GA) and fuzzy mathematical programming make the search for optimal control strategies in an uncertain environment more feasible. Using a probabilistic search procedure that emulates Darwinian natural selection, GAs allow multicriteria decision making with respect to both nonlinear feature and fuzzy characteristics to be incorporated directly into the optimization process and generate trade-off curves between cost and environmental quality while identifying good control strategies. This paper verifies such a discovery by a case study of water quality control in the Tseng-Wen river basin in Taiwan.

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Moosavian, Naser, and Mohammad Reza Jaefarzadeh. "Hydraulic Analysis of Water Distribution Network Using Shuffled Complex Evolution." Journal of Fluids 2014 (January 16, 2014): 1–12. http://dx.doi.org/10.1155/2014/979706.

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Hydraulic analysis of water distribution networks is an important problem in civil engineering. A widely used approach in steady-state analysis of water distribution networks is the global gradient algorithm (GGA). However, when the GGA is applied to solve these networks, zero flows cause a computation failure. On the other hand, there are different mathematical formulations for hydraulic analysis under pressure-driven demand and leakage simulation. This paper introduces an optimization model for the hydraulic analysis of water distribution networks using a metaheuristic method called shuffled complex evolution (SCE) algorithm. In this method, applying if-then rules in the optimization model is a simple way in handling pressure-driven demand and leakage simulation, and there is no need for an initial solution vector which must be chosen carefully in many other procedures if numerical convergence is to be achieved. The overall results indicate that the proposed method has the capability of handling various pipe networks problems without changing in model or mathematical formulation. Application of SCE in optimization model can lead to accurate solutions in pipes with zero flows. Finally, it can be concluded that the proposed method is a suitable alternative optimizer challenging other methods especially in terms of accuracy.

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Sunarsih, Widowati, Kartono, and Sutrisno. "Mathematical Analysis for the Optimization of Wastewater Treatment Systems in Facultative Pond Indicator Organic Matter." E3S Web of Conferences 31 (2018): 05008. http://dx.doi.org/10.1051/e3sconf/20183105008.

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Stabilization ponds are easy to operate and their maintenance is simple. Treatment is carried out naturally and they are recommended in developing countries. The main disadvantage of these systems is large land area they occupy. The aim of this study was to perform an optimization of the wastewater treatment systems in a facultative pond, considering a mathematical analysis of the methodology to determine the model constrains organic matter. Matlab optimization toolbox was used for non linear programming. A facultative pond with the method was designed and then the optimization system was applied. The analyse meet the treated water quality requirements for the discharge to the water bodies. The results show a reduction of hydraulic retention time by 4.83 days, and the efficiency of of wastewater treatment of 84.16 percent.

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Lv, Ziqiang, Jiuju Cai, Wenqiang Sun, and Lianyong Wang. "Analysis and Optimization of Open Circulating Cooling Water System." Water 10, no. 11 (November 7, 2018): 1592. http://dx.doi.org/10.3390/w10111592.

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Open circulating cooling water system is widely used in process industry. For a system with a fixed structure, the water consumption and blowdown usually change with the varying parameters such as quality and temperature. With the purpose of water saving, it is very important to optimize the operation strategy of water systems. Considering the factors including evaporation, leakage, blowdown and heat transfer, the mass and energy conservation equations of water system are established. On this basis, the quality and temperature models of makeup and blowdown water are, respectively, developed. The water consumption and discharge profiles and the optimal operating strategy of the open recirculating cooling water system under different conditions are obtained. The concept of cycles of temperature is proposed to evaluate the temperature relationship of various parts of the open circulating cooling water system. A mathematical relationship is established to analyze the influence of the water temperature on the makeup water rate of the system under the condition of insufficient cooling capacity of the cooling tower. In addition, the co-influences of quality and temperature parameters on the system are analyzed.

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Gong, Yi, and Jilin Cheng. "Combinatorial Optimization Method for Operation of Pumping Station with Adjustable Blade and Variable Speed Based on Experimental Optimization of Subsystem." Advances in Mechanical Engineering 6 (January 1, 2014): 283520. http://dx.doi.org/10.1155/2014/283520.

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A decomposition-dynamic programming aggregation method based on experimental optimization for subsystem was proposed to solve mathematical model of optimal operation for single pumping station with adjustable blade and variable speed. Taking minimal daily electric cost as objective function and water quantity pumped by units as coordinated variable, this model was decomposed into several submodels of daily optimal operation with adjustable blade and variable speed for single pump unit which was solved by experimental optimization. The constructed aggregation model took water quantity pumped by each pump unit as decision variable and discrete values of water quantity pumped by pumping station as state variable and was solved by one-dimensional dynamic programming. Taking operation of typical pumping station as a study case, optimal operation with adjustable blade and variable speed, respectively, had an average cost saving of 4.19%, 22.15%, and 29.86% compared with operation with fixed blade angle and constant speed under 100%, 80%, and 60% load, which also had a remarkable saving amplitude of 15.85% and 24.18%, respectively, corresponding to 80% load and 60% load compared with operation with adjustable blade and constant speed. Meanwhile, the proposed method has provided a new way for solving complex nonlinear mathematical models with 3 decision variables.

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Nyers, Jozsef. "An analytical method for defining the pump`s power optimum of a water-to-water heat pump heating system using COP." Thermal Science 21, no. 5 (2017): 1999–2010. http://dx.doi.org/10.2298/tsci161110324n.

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This paper analyzes the energy efficiency of the heat pump and the complete heat pump heating system. Essentially, the maximum of the coefficient of performance of the heat pump and the heat pump heating system are investigated and determined by applying a new analytical optimization procedure. The analyzed physical system consists of the water-to-water heat pump, circulation and well pump. In the analytical optimization procedure the "first derivative equal to zero" mathematical method is applied. The objective function is the coefficient of performance of the heat pump, and the heat pump heating system. By using the analytical optimization procedure and the objective function, as the result, the local and the total energy optimum conditions with respect to the mass flow rate of hot and cold water i. e. the power of circulation or well pump are defined.

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Ayesa, E., B. Goya, A. Larrea, L. Larrea, and A. Rivas. "Selection of operational strategies in activated sludge processes based on optimization algorithms." Water Science and Technology 37, no. 12 (June 1, 1998): 327–34. http://dx.doi.org/10.2166/wst.1998.0558.

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This paper presents a new optimization algorithm for the selection of design and operation parameters in complex Activated Sludge (AS) processes. The algorithm estimates automatically the dimensions and operating point of the plant that minimize a global penalty function combining effluent requirements and costs. The mathematical optimization is based on a direct search algorithm integrated in a previously developed simulation package. Some illustrative examples concerning the design and operation of the Alpha process have been included to show the potential of this kind of mathematical tool when the complexity of plant configuration increases. The results obtained by the optimization procedure generate useful guidelines for the design and operation and suggest a great potential in the application for solving more complex problems when additional objectives and costs are included.

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Lizarralde, I., F. Claeys, R. Ordóñez, M. de Gracia, L. Sancho, and P. Grau. "Water network cost optimization in a paper mill based on a new library of mathematical models." Water Science and Technology 65, no. 11 (June 1, 2012): 1929–38. http://dx.doi.org/10.2166/wst.2012.083.

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The increasing costs associated with water supply and the disposal of wastewater has stimulated industries to seek more efficient water management systems. Mathematical modelling and simulation can be a very valuable tool for the study of the multiple alternatives available whilst assessing optimum solutions for water management in industry. This study introduces a new steady state model library able to reproduce industrial water circuits. It has been implemented in a novel software framework for the representation, simulation and optimization of industrial water networks. A water circuit representing a paper mill has been modelled and simulated showing the capability to reproduce real case studies. Alternative scenarios for the water network have also been tested to assess the capability of the models to optimize water circuits minimizing total cost.

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Sidorenko, Gennady Ivanovich, and Artem Surenovich Alimirzoev. "Multicriterion Optimization of Power Sites Location on the Watercourse." Applied Mechanics and Materials 725-726 (January 2015): 293–98. http://dx.doi.org/10.4028/www.scientific.net/amm.725-726.293.

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In this article we have explored the issue of optimization of HPP site location in a cascade depending on social-economic, environmental and energy limitations taking into account available cadastre of water power resources. A multicriterion problem of optimization on the network was formulated. Pareto optimal solution of this problem was obtained by means of the developed mathematical model of optimization of the HPP site location in the cascade. The optimization algorithm to solve this problem has been developed

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Zhao, Hong Wei, and Li Wei Tian. "Optimization of Multi-Objective Coverage Strategy Based on Multiple Particle Swarm Coevolutionary Algorithm for Water Environment Monitoring System." Applied Mechanics and Materials 742 (March 2015): 360–63. http://dx.doi.org/10.4028/www.scientific.net/amm.742.360.

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This paper built a multi-objective optimization model and proposed an improved multi-objective particle swarm optimization algorithm called MPS2O ,which is based on Multiple Particle Swarm Co-evolutionary. The MPS2O algorithm has considerable potential for solving multi-objective optimization problems. Mathematical benchmark functions also shows that the proposed algorithm is an excellent Alternative for solving multi-objective optimization problems. Making full use of the research findings home and abroad, MPS2O has been chosen to be the coverage optimization strategy of the wireless sensor networks in Water Environment Monitoring System. Simulation results demonstrate that the MPS2O algorithm is more efficient than the PSO algorithm in solving this real-world problem.

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Choi and Kim. "Self-Adaptive Models for Water Distribution System Design Using Single-/Multi-Objective Optimization Approaches." Water 11, no. 6 (June 20, 2019): 1293. http://dx.doi.org/10.3390/w11061293.

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This study compares the performance of self-adaptive optimization approaches in efficient water distribution systems (WDS) design and presents a guide for the selection of the appropriate method employing optimization utilizing the characteristic of each technique formulation. To this end, this study performs three types of analyses. First, the sensitivity analysis of each self-adaptive approach is conducted on single/multi-objective mathematical benchmark problems with various problem types (e.g., using solution shape or many local optimal solutions). Second, based on the applications and results of the mathematical problem, the performance of the algorithm is verified in the WDS design problem considering the minimum cost and the maximum system resilience under the single/multi-objective optimization framework. Third, the characteristics of search operators in the self-adaptive approach are compared according to the presence or absence of additional parameters and operators. Moreover, various performance indices are employed to compare the quantitative evaluation of each algorithm. Each algorithm is found to exhibit different characteristics depending on the problem scale and solution type. These results are expected to benefit future research in the formulation of new approaches and developments. Hence, this study provides rigorous testing of the performance of newly proposed algorithms in a highly simplified manner.

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Eryiğit, Miraç. "Cost optimization of water distribution networks by using artificial immune systems." Journal of Water Supply: Research and Technology-Aqua 64, no. 1 (July 19, 2014): 47–63. http://dx.doi.org/10.2166/aqua.2014.031.

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This study aims at the development of an optimization model based on artificial immune systems (AIS) to minimize cost designs of water distribution networks (WDNs). Clonal selection algorithm (Clonalg), a class of AIS, was used as an optimization technique in the model, and its mutation operation was modified to increase the diversity (search capability). EPANET, a widely known WDN simulator, was used in conjunction with the proposed model. The model was applied to four WDNs of Two-loop, Hanoi, Go Yang, New York City, and the results obtained were compared with other heuristic and mathematical optimization models in the related literature, such as harmony search, genetic algorithm, immune algorithm, shuffled complex evolution, differential evolution, and non-linear programming-Lagrangian algorithm. Furthermore, the modified Clonalg was compared with the classic Clonalg in order to demonstrate the impact of the modification on the diversity. The proposed model appeared to be promising in terms of cost designs of WDNs.

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Kong, Chan, Yong Sun, Hongxi Zhang, and Yongjiang Shi. "Mathematical Analysis of Optimal Operating Conditions in Heating Systems." Mathematical Problems in Engineering 2019 (May 6, 2019): 1–16. http://dx.doi.org/10.1155/2019/4264562.

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With changes in the outdoor air temperature, the heat consumption of buildings also changes. Timely adjustment of the heating systems to ensure optimal operating conditions is extremely significant to save energy. In this study, the operation conditions of a heating system were analyzed numerically, and the existence, uniqueness, and stability of the optimal operation conditions of the heating system were proved. An operation optimization model that could obtain the optimal operation conditions was also established, and the correctness of the model was verified experimentally. Experimental results showed that when the flow rate was 0.606 m3/h, the supply water temperature was 67.13°C, water return temperature was 65.90°C, and the pump consumed the least amount of electricity. The experimental results and model calculation results showed that the operating cost is lower when the system flow rate is low and the supply water temperature is high under the same heat dissipation and indoor temperature.

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Elmitwalli, Tarek. "Mathematical modeling of upflow anaerobic sludge blanket (UASB) reactor treating domestic wastewater." Water Science and Technology 67, no. 1 (January 1, 2013): 24–32. http://dx.doi.org/10.2166/wst.2012.512.

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Although the upflow anaerobic sludge blanket (UASB) reactor has been widely applied for domestic wastewater treatment in many developing countries, there is no sufficient mathematical model for proper design and operation of the reactor. An empirical model based on non-linear regression was developed to represent the physical and chemical removal of suspended solids (SS) in the reactor. Moreover, a simplified dynamic model based on ADM1 and the empirical model for SS removal was developed for anaerobic digestion of the entrapped SS and dissolved matter in the wastewater. The empirical model showed that effluent suspended chemical oxygen demand (CODss) concentration is directly proportional to the influent CODss concentration and inversely proportional to both the hydraulic retention time (HRT) of the reactor and wastewater temperature. For obtaining sufficient CODss removal, the HRT of the UASB reactor must be higher than 4 h, and higher HRT than 12 h slightly improved CODss removal. The dynamic model results showed that the required time for filling the reactor with sludge mainly depends on influent total chemical oxygen demand (CODt) concentration and HRT. The influent CODt concentration, HRT and temperature play a crucial role on the performance of the reactor. The results indicated that shorter HRT is needed for optimization of CODt removal, as compared with optimization of CODt conversion to methane. Based on the model results, the design HRT of the UASB reactor should be selected based on the optimization of wastewater conversion and minimization of biodegradable SS accumulation in the sludge bed, not only based on COD removal, to guarantee a stable reactor performance.

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Liu, J., Y. P. Li, and G. H. Huang. "Mathematical Modeling for Water Quality Management under Interval and Fuzzy Uncertainties." Journal of Applied Mathematics 2013 (2013): 1–14. http://dx.doi.org/10.1155/2013/731568.

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In this study, an interval fuzzy credibility-constrained programming (IFCP) method is developed for river water quality management. IFCP is derived from incorporating techniques of fuzzy credibility-constrained programming (FCP) and interval-parameter programming (IPP) within a general optimization framework. IFCP is capable of tackling uncertainties presented as interval numbers and possibility distributions as well as analyzing the reliability of satisfying (or the risk of violating) system’s constraints. A real-world case for water quality management planning of the Xiangxi River in the Three Gorges Reservoir Region (which faces severe water quality problems due to pollution from point and nonpoint sources) is then conducted for demonstrating the applicability of the developed method. The results demonstrate that high biological oxygen demand (BOD) discharge is observed at the Baishahe chemical plant and Gufu wastewater treatment plant. For nonpoint sources, crop farming generates large amounts of total phosphorus (TP) and total nitrogen (TN). The results are helpful for managers in not only making decisions of effluent discharges from point and nonpoint sources but also gaining insight into the tradeoff between system benefit and environmental requirement.

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Wang, Zhao Feng, Man Yao, Xiao Bing Zhang, and Xu Dong Wang. "Optimization Control for Solidification Process of Secondary Cooling in Continuous Casting Steel." Applied Mechanics and Materials 263-266 (December 2012): 822–27. http://dx.doi.org/10.4028/www.scientific.net/amm.263-266.822.

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In order to predict and control the temperature of continuous casting slab, a mathematical heat transfer model simulating the solidification process of continuous casting slab has been developed based on the realistic roller-layout and spray nozzle distribution. And the accuracy has been verified by comparing with the pin-shooting experiment results. An advanced control strategies are adopted to achieve the optimization of water quantity under different production conditions by the integration of energy saving water distribution module and slab temperature optimization module in the dynamic secondary cooling model. The total water consumption has a trend of dropping off after the utilization of the optimization technique. And the slab surface temperature increases which fits for the down stream direct hot rolling.

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Egereva, Elvira, Alexei Barmenkov, and Alina Barmenkova. "Effect of activated sealant water on strength of cement samples." E3S Web of Conferences 284 (2021): 05007. http://dx.doi.org/10.1051/e3sconf/202128405007.

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The article presents the results of optimization of the cement composition according to the criteria of compressive strength and bending by methods of mathematical planning of the experiment. As a result of the studies, cement compositions of increased strength were obtained using activated closure water, as well as using tandem activated water (AB) + plasticizer and AB + adhesive additive. At optimal content of components, strength gain of up to 18% is achieved.

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Ferent-Pipas, Silvia, Bogdan Padurean, and Cornel Ciupan. "Mathematical Model for the Calculation of Linear Speed for a Water Jet Cutting Machine." Applied Mechanics and Materials 332 (July 2013): 411–16. http://dx.doi.org/10.4028/www.scientific.net/amm.332.411.

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This article is about creating a mathematical model for the calculation of linear speed, of a water jet machine, depending on the thickness of the material, the water pressure, the abrasive rate flow and the required cut quality, in order to justify the cutting costs of a water jet machine that are directly proportional with the necessary cutting time. Finding the cutting speed, it can be find the necessary time for the cutting, and so, the resulting costs for the process. The optimization of the process, after some minimize and maximize criteria is also presented in this article.

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Burn, Donald H., and Edward A. McBean. "Linear stochastic optimization applied to biochemical oxygen demand – dissolved oxygen modelling." Canadian Journal of Civil Engineering 13, no. 2 (April 1, 1986): 249–54. http://dx.doi.org/10.1139/l86-033.

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A methodology for reflecting stochastic considerations in an optimization model is presented. The technique, which uses chance-constrained programming, is applied to a water quality management problem wherein concern is with the interaction between biochemical oxygen demand (BOD) and the dissolved oxygen (DO) concentration in a river. The uncertainty in the problem is considered to be embodied in transfer coefficients for which a lognormal distribution is derived from moment estimates provided by first-order uncertainty analysis. The appropriateness of the lognormal distribution is confirmed by results from a simulation modelling exercise. Key words: water quality, optimization, uncertainty, mathematical modelling.

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Сазонова and Svetlana Sazonova. "THE PROBLEM OF PARAMETRIC OPTIMIZATION AND SECURITY OF FUNCTIONING OF HYDRAULIC SYSTEMS." Modeling of systems and processes 9, no. 1 (September 23, 2016): 48–51. http://dx.doi.org/10.12737/21628.

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Problem definition of parametrical optimization of hydraulic systems is considered. The general problem of parametrical optimization for systems of water supply and gas supply is presented in the form of a problem of mathematical programming. As a result of the solution of the considered task optimum parameters of the studied systems have to be determined, the required levels of reliability and safety when functioning are ensured.

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Wei, Li Xin, Ren Shan Pang, and Zhi Hua Wang. "Temperature Drop Transportation Scheme Optimization of Oil Gathering and Transportation System in Weixing Oilfield." Applied Mechanics and Materials 143-144 (December 2011): 376–80. http://dx.doi.org/10.4028/www.scientific.net/amm.143-144.376.

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Wax crystallization characteristics, properties of viscosity-temperature and cold rheological properties of crude oil systems with different water cut are studied to analyze the feasibility and advantages of developing temperature drop gathering and transportation in Weixing Oilfield. On the basis of the characteristics of single pipe loop gathering and transportation technological process, an optimization mathematical model for oil gathering and transporting system operation is established, which objective function is the minimum energy consumption of the system. And to solve the model, the hierarchic optimization strategy is adopted. Optimization results of No.1 department and No.2 department showed that the water blending temperature is reduced more than 8°C and the water blending amount is decreased 20%. According to the optimization scheme, the saving on gas and electricity are 7.12×105m3 and 8.92×105kW•h each year.

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Studzinski, Jan. "ICS System Supporting the Water Networks Management by Means of Mathematical Modelling and Optimization Algorithms." Journal of Automation, Mobile Robotics & Intelligent Systems 9, no. 4 (November 24, 2015): 48–54. http://dx.doi.org/10.14313/jamris_4-2015/32.

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Journal articles on the topic 'Water Mathematical optimization'

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